Image display apparatus and method of controlling the same

ABSTRACT

Provided are an image display apparatus and a method of controlling the same. The image display apparatus enabling voice recognition includes: a first voice inputter which receives a user-side audio signal; an audio outputter which outputs an audio signal processed by the image display apparatus; a first voice recognizer which recognizes the user-side audio signal received through the first voice inputter; and a controller which decreases a volume of the audio signal output through the audio outputter to a predetermined level if a voice recognition start command is received.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. patent application Ser. No.14/678,556, filed Apr. 3, 2015, which is a continuation application ofU.S. patent application Ser. No. 13/737,683, filed on Jan. 9, 2013, nowU.S. Pat. No. 9,401,149, issued Jul. 26, 2016, which claims priorityfrom Korean Patent Application No. 10-2012-0002659, filed on Jan. 9,2012 in the Korean Intellectual Property Office, and Korean PatentApplication No. 10-2012-0143590, filed on Dec. 11, 2012 in the KoreanIntellectual Property Office, the disclosures of which are incorporatedherein by reference in their entireties.

BACKGROUND

1. Field

Apparatuses and methods consistent with exemplary embodiments relate toan image display apparatus that executes a command through voicerecognition and a method of controlling the same.

2. Description of the Related Art

In general, an image display apparatus, e.g., a television (TV),processes and outputs a video signal in various formats. Recently, as adigital TV having a signal processing and a storage capacity superior toexisting analog TVs has been developed and commercially used, variouskinds of content services, such as real-time broadcast, content ondemand (COD), games and video communication, may be provided to usersusing an Internet network installed in each home.

In addition, when an image display apparatus receives a command from auser in order to perform various functions including various kinds ofservices, a voice recognition method of receiving a user voice through amicrophone, recognizing the received user voice, and executing a commandcorresponding to the received user voice has been applied.

However, when the user voice is received through the microphone,background sound is also received and, more particular, an audio signaloutput from the image display apparatus may be received. If the volumeof the background sound or the audio signal output of the image displayapparatus exceeds a predetermined level, a user voice recognition rateof the image display apparatus may be decreased.

SUMMARY

Therefore, aspects of one or more exemplary embodiments provide an imagedisplay apparatus able to improve voice recognition performance bydecreasing the volume of an audio signal output from the image displayapparatus to a predetermined level or less when the image displayapparatus recognizes a user voice, and a method of controlling the same.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be obvious from the description, or may belearned by practice of exemplary embodiments.

According to an aspect of an exemplary embodiment, there is provided animage display apparatus enabling voice recognition, the image displayapparatus including: a first voice inputter which receives a user-sideaudio signal; an audio outputter which outputs an audio signal processedby the image display apparatus; a first voice recognizer which analyzesthe user-side audio signal received through the first voice inputter;and a controller which decreases a volume of the output audio signal toa predetermined level if a voice recognition start command is received,the voice recognition start command indicating a start of a voicerecognition in the analyzed user-side audio signal.

The voice recognition start command may be received as a voice signal ofa user through the first voice inputter.

The controller may determine that the voice recognition start command isreceived if a voice recognition start command word is received throughthe first voice inputter.

The controller may determine that the voice recognition start command isreceived if voice having a predetermined volume or more is receivedthrough the first voice inputter.

The image display apparatus may further include a background soundcanceller to reduce background sound other than the voice signal of theuser from the user-side audio signal.

The background sound canceller may reduce audio output through the audiooutputter from the user-side audio signal received through the firstvoice inputter.

The controller may return the volume of the output audio signal to avolume of the audio signal when the voice recognition begins.

The controller may determine that the voice recognition ends if acontrol command of the user is not received through the first voiceinputter for a predetermined voice recognition end time or more.

The controller may request the user to input a control command if thecontrol command of the user is not received through the first voiceinputter for a predetermined command request time or more.

The controller may determine that voice recognition ends if a voicerecognition end command word is received through the first voiceinputter.

The image display apparatus may further include a command word generatorto generate a voice recognition start command word corresponding to thevoice recognition start command.

The command word generator may receive a candidate command word throughthe first voice inputter, test whether the candidate command word issuitable as the voice recognition start command word, and register thecandidate command word as the voice recognition start command if thecandidate command word is suitable as the voice recognition startcommand word.

The command word generator may receive a selection command from the userand select and set the voice recognition start command word according tothe received selection command if the number of registered voicerecognition command words is two or more.

The image display apparatus may further include a remote controllerwhich remotely controls the image display apparatus, and the remotecontroller may include an input button which receives a control commandof a user, a second voice inputter which receives a user-side audiosignal, and a second voice recognizer which analyzes the user-side audiosignal received through the second voice inputter.

The controller may determine that the voice recognition start command isreceived if voice having a predetermined volume or more is receivedthrough the second voice inputter.

The controller may return the volume of the audio signal output throughthe audio output unit to the volume of the audio signal when the voicerecognition begins, if the voice recognition ends.

The controller may determine that the voice recognition ends if thecontrol command of the user is not received through the second voiceinputter for a predetermined voice recognition end time or more.

The controller may request the user to input a control command if thecontrol command of the user is not received through the second audioinputter for a predetermined command request time or more.

The controller may determine that voice recognition ends if a voicerecognition end command is received through the input button or thesecond voice inputter.

According to an aspect of another exemplary embodiment, there isprovided an image display apparatus enabling voice recognition, theimage display apparatus including: a voice inputter which receives acontrol command word from a user; and a display which displays at leastone icon corresponding to a plurality of control command words and whichchanges an icon, among the at least one icon, corresponding to thereceived control command word if the control command word is receivedfrom the user through the voice inputter.

According to an aspect of another exemplary embodiment, there isprovided a method of controlling an audio outputting apparatus includingan audio outputter, the method including: receiving a user-side audiosignal from a user; determining whether the received user-side audiosignal corresponds to a voice recognition start command word; anddecreasing a volume of an audio signal output through the audiooutputter to a predetermined level if the received user-side audiosignal corresponds to the voice recognition start command word.

The method may further include reducing a background sound signal otherthan a voice signal of the user from the user-side audio signal if theuser-side audio signal is received through the voice inputter.

The background sound signal may be an audio signal output through theaudio outputter.

The method may further include returning the volume of the output audiosignal to a volume of the audio signal when voice recognition begins, ifthe voice recognition ends.

Ending of the voice recognition may include determining that the voicerecognition ends if a control command of the user is not receivedthrough the voice inputter for a predetermined voice recognition endtime or more.

Ending of voice recognition may include determining that the voicerecognition ends if a voice recognition end command word is receivedthrough the voice inputter.

According to an aspect of another exemplary embodiment, there isprovided a method of controlling a processing apparatus enabling voicerecognition, the method including: receiving a candidate command wordfrom a user through a voice inputter; testing whether the receivedcandidate command word is suitable as a control command word to besubjected to the voice recognition; and registering the candidatecommand word as the control command if the candidate command word issuitable as the control command word according to the testing.

According to an aspect of another exemplary embodiment, there isprovided a method of controlling a processing apparatus, the methodincluding: decreasing a volume of an audio signal output from theprocessing apparatus to a predetermined volume if a voice recognitionstart command is received from the user through a voice inputter of theprocessing apparatus or a remote controller; and returning the volume ofthe output audio signal to an original level if a voice recognition endcommand is received from the user.

The receiving the voice recognition start command may include receivingthe voice recognition start command of the user through the voiceinputter.

The receiving the voice recognition start command may include receivingvoice having a predetermined volume or more through the voice inputter.

The receiving the voice recognition end command may include receiving avoice recognition end command word of the user through the voiceinputter.

The voice recognition end command may be received when the controlcommand is not received through the voice inputter for a predeterminedvoice recognition end time or more.

According to an aspect of another exemplary embodiment, there isprovided a processing apparatus, including: an audio output controllerwhich controls an output of an audio signal; and a controller which, inresponse to determining that a voice recognition starts, performs atleast one of decreasing a volume of the output audio signal to apredetermined level and reducing a background sound other than a voicesignal of a user from a user-side audio signal received from the user.

According to aspects of one or more exemplary embodiments, it ispossible to improve user voice recognition performance of an imagedisplay apparatus and prevent malfunction of the image display apparatusdue to voice recognition errors.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of exemplary embodiments,taken in conjunction with the accompanying drawings of which:

FIG. 1 is a diagram showing the appearance of an image display apparatusaccording to an exemplary embodiment;

FIG. 2 is a block diagram showing a control flow of an image displayapparatus main body according to an exemplary embodiment;

FIG. 3 is a block diagram showing a control flow of an image displayapparatus according to an exemplary embodiment, which further includes abackground sound canceller;

FIG. 4 is a block diagram showing a control flow of an image displayapparatus according to an exemplary embodiment, which further includes acommand word generator;

FIG. 5 is a diagram showing the appearance of a remote controllerincluded in an image display apparatus according to an exemplaryembodiment;

FIG. 6 is a block diagram showing a control flow of a remote controllerincluded in an image display apparatus according to an exemplaryembodiment;

FIG. 7 is a flowchart illustrating a control method of an image displayapparatus according to an exemplary embodiment;

FIG. 8 is a flowchart illustrating the exemplary embodiment of FIG. 7 ingreater detail;

FIG. 9 is a flowchart illustrating a control method of an image displayapparatus according to another exemplary embodiment;

FIG. 10 is a flowchart illustrating a control method of an image displayapparatus according to another exemplary embodiment;

FIG. 11 is a flowchart illustrating a method of finishing voicerecognition if a control command is not received from a user throughvoice for a predetermined time in FIG. 9, according to an exemplaryembodiment;

FIGS. 12A-12C are diagrams showing a screen displayed on a video outputunit if an image display apparatus according to an exemplary embodimentis in a voice recognition mode;

FIG. 13 is a flowchart illustrating a method of generating a commandword by a user in an image display apparatus according to an exemplaryembodiment; and

FIGS. 14A-14D are diagrams showing a screen displayed on a video outputunit if an image display apparatus according to an exemplary embodimentgenerates a command word by a user.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiment described in the present specification and theconfigurations shown in the drawings are merely exemplary and variousmodifications may be made thereto.

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings.

FIG. 1 is a diagram showing the appearance of an image display apparatus1 according to an exemplary embodiment.

Referring to FIG. 1, the image display apparatus 1 includes an imagedisplay apparatus main body 100 to output at least one of video andaudio according to a control command of a user, and a remote controller300 to remotely control the image display apparatus main body 100.

The image display apparatus main body 100 may be implemented by adigital TV and includes a video output unit 121 (e.g., video outputter)to output a video signal of a broadcast program and a video signal of avariety of content, an audio output unit 122 (e.g., audio outputter) tooutput an audio signal of a broadcast program and an audio signal of avariety of content, and a user input unit 110 (e.g., user inputter) toacquire a control command through user voice or operation.

The image display apparatus 1 according to the present exemplaryembodiment enables video communication through a wired and/or wirelessnetwork. If the image display apparatus 1 provides a video communicationservice, it is possible to output a video signal of the other party ofthe video communication service through the video output unit 121 and tooutput an audio signal of the other party through the audio output unit122. In this case, the video signal and the audio signal of the user maybe acquired through the user input unit 110 and transmitted to the otherparty.

The audio output unit 122 may be implemented by a speaker, etc., andoutput an audio signal processed by the image display apparatus 1. Morespecifically, the audio output unit 122 outputs an audio signal includedin a broadcast program signal or an audio signal included in contentexecuted by the image display apparatus 1. In addition, as describedabove, if the image display apparatus 1 performs a video communicationoperation, an audio signal of the other party may be output. Althoughthe image display apparatus 1 of the present exemplary embodimentincludes the audio output unit 122 at the rear side thereof, it isunderstood that one or more other exemplary embodiments are not limitedthereto and the audio output unit 122 may be mounted at any place whereaudio is provided to a user.

The video output unit 121 outputs a video signal processed in the imagedisplay apparatus 1. More specifically, the video output unit 121outputs a video signal included in a broadcast program signal or a videosignal included in content in the image display apparatus 1. Inaddition, if the image display apparatus 1 performs a videocommunication operation, a video signal of the other party of the videocommunication may be output.

The user input unit 110 includes an image input unit 111 (e.g., imageinputter) to receive an image of a user and a first voice input unit 112(e.g., first voice inputter) to receive user voice.

The image input unit 111 includes a lens to receive an image of a user,an imaging device to capture the image of the user through the lens,such as a charge coupled device (CCD) sensor or a complementarymetal-oxide semiconductor (CMOS) sensor, and an image signal processor(ISP) to process the image captured by the imaging device.

The first voice input unit 112 may be implemented by a microphone, etc.,and receives a user voice. However, the first voice input unit 112 mayreceive background sound and, more particularly, an audio signal outputfrom the audio output unit 122 of the image display apparatus 1, inaddition to the user voice. Accordingly, in the following disclosure, asignal received through the first voice input unit 112, i.e., an audioof a surrounding environment surrounding the image display apparatus 1or another device which captures the signal (e.g., a remote controller),is referred to as a “user-side audio signal.” The user-side audio signalmay include not only a user voice signal, but also a background soundsignal.

As shown in FIG. 1, although the image display apparatus 1 includes aMultimedia over Internet Protocol (MoIP) device in which a video inputunit 111 and a voice input unit 112 are integrally included, it isunderstood that one or more other exemplary embodiments are not limitedthereto and the image display apparatus 1 may include the first voiceinput unit 112 and not the image input unit 111.

Instead of pressing an input button included in the remote controller300 or the image display apparatus main body 100, a user may input acontrol command as a voice signal to the image display apparatus 1according to an exemplary embodiment through the first voice input unit112, thereby controlling an operation of the image display apparatus 1.For example, as shown in FIG. 1, if various content menus are displayedon the video output unit 121, the user may select a menu by inputting acommand word corresponding to a desired menu to the first voice inputunit 112 as a voice signal.

The user input unit 110 may be implemented separately from the imagedisplay apparatus main body 100 as shown in FIG. 1 or integrally withthe image display apparatus main body 100.

FIG. 2 is a block diagram showing a control flow of an image displayapparatus main body 100 according to an exemplary embodiment.

Referring to FIG. 2, the image display apparatus main body 100 accordingto the present exemplary embodiment includes a broadcast signal receiver230 to receive a broadcast signal, a content execution unit 240 (e.g.,content executor) to execute content, a video processor 251 to process avideo signal in the received broadcast signal or a video signal includedin the content, an audio processor 252 to process an audio signalincluded in the received broadcast signal or an audio signal included inthe content, a video output unit 121 (e.g., video outputter) to outputthe video signal processed by the video processor 251, an audio outputunit 122 (e.g., audio outputter) to output the audio signal processed bythe audio processor 252, a first voice input unit 112 to receive a voicesignal from a user, a first voice recognizer 210 to recognize a controlcommand based on the voice signal received from the user, a firstcommunication unit 260 (e.g., first communicator) to receive a controlsignal from the remote controller 300, and a first controller 220 tocontrol an overall operation of the image display apparatus main body100.

The broadcast signal receiver 230 receives a broadcast signal includinga video signal and an audio signal. The broadcast signal receiver 230includes an antenna and a tuner, outputs the video signal through thevideo output unit 121, and outputs the audio signal through the audiooutput unit 122.

The content execution unit 240 executes multimedia content. Themultimedia content executed by the content execution unit 240 may be agame, a moving image file, a music file, etc., stored in the imagedisplay apparatus 1 or a variety of multimedia content provided over theInternet if the image display apparatus 1 is connected to the Internetby wire or wirelessly. In addition, if the image display apparatus isconnected to another external device such as a mobile communicationapparatus or a computer, the multimedia content may be provided by theconnected external apparatus and the kind of the multimedia contentexecuted by the content execution unit 240 is not limited.

The audio processor 252 processes the audio signal received from thebroadcast signal receiver 230 and the content execution unit 240 andoutputs the processed audio signal through the audio output unit 122.The audio processor 252 may include a decoder to decode a signalcompressed in a predetermined format, such as a broadcast audio signal,and a digital/analog converter to convert the digital signal into ananalog signal, and transmits the analog signal to the audio output unit122.

The video processor 251 processes the video signal received from thebroadcast signal receiver 230 and the content execution unit 240 andoutputs the processed video signal through the video output unit 121.The video processor 251 may include a decoder to decode a signalcompressed in a predetermined format, such as a broadcast video signal,and a digital/analog converter to convert the digital signal into ananalog signal, and transmits the analog signal to the video output unit121.

The first voice input unit 112 receives a voice signal related to acontrol command from the user. The first voice input unit 112 may beimplemented by a microphone or may be implemented by an MoIP device inwhich a microphone and a camera are integrally included, e.g., as shownin FIG. 1. In addition, the first voice input unit 112 may amplify thereceived user-side audio signal, convert the amplified user-side audiosignal from an analog signal into the digital signal, and transmit thedigital signal to the first voice recognizer 210.

The first voice input unit 112 may include a voice encoder. If the firstvoice input unit 112 is connected to the image display apparatus mainbody 100 through a data interface, the voice encoder may compress theuser-side audio signal into a format suitable for a bandwidth of thedata interface or compress the user-side audio signal into a formatcapable of being transmitted to the other party of a video communicationif the video communication is performed. In this case, the image displayapparatus main body 100 may include a voice decoder to decode thecompressed user-side audio signal before voice recognition.

As described above, when the first voice input unit 112 receives uservoice, background sound may also be received. Thus, the first voiceinput unit 112 receives the user-side audio signal including a uservoice signal. When the user inputs a control command through the firstaudio input unit 112, since the image display apparatus 1 is operating,the user-side audio signal may include the user voice signal and theaudio signal output through the audio output unit 122.

The first voice recognizer 210 analyzes the user voice signal receivedthrough the first voice input unit 112 and recognizes the controlcommand input by the user. The voice recognition method may include atleast one of a pattern matching method of comparing a received voicesignal with a previously stored standard pattern and detecting a voicepattern most similar to the received voice signal, an identificationfunction method of setting a function for distinguishing between oneword and another word in advance, applying the set function to a uservoice signal, and determining the user voice signal, etc. In addition,voice recognition may be performed in word units or phoneme units. Asthe voice recognition method of the voice recognizer 210, any relatedart method may be employed and exemplary embodiments are not limited tothe above-described methods.

The first communication unit 260 receives a control signal from theremote controller 300 and provides the control signal to the firstcontroller 220. The first communication unit 260 may employ not only awireless communication scheme such as a Wi-Fi communication scheme, aBluetooth communication scheme, a ZigBee communication scheme, etc., butalso an infrared communication scheme having a relatively simpleconfiguration.

The first controller 220 receives the recognition result from the firstvoice recognizer 210 and performs a control according to the recognitionresult. For example, if the control command according to the recognitionresult is broadcast channel change, a control signal is sent to thebroadcast signal receiver 230 to change the channel according to thecontrol command and, if the control command according to the recognitionresult is content selection, a control signal is sent to the contentexecution unit 240 to execute the content according to the controlcommand.

The first controller 220 decreases the volume of the audio signal outputfrom the audio output unit 122 to a predetermined level if the controlcommand transmitted by the first voice recognizer 210 is a voicerecognition start command. If a predetermined voice recognition startcommand word is received through the first voice input unit 112 or ifvoice having a predetermined reference volume or more is received, thefirst voice recognizer 210 recognizes the received command or voice asthe voice recognition start command and transmits the voice recognitionstart command to the first controller 220. The first controller 220 mayreceive the voice recognition start command, switch the image displayapparatus 1 to a voice recognition mode, and decrease the volume of theaudio output unit 122 to a predetermined level.

In reception of the voice recognition start command through the voicerecognition start command word, the voice recognition start command wordmay be set to a simple word capable of easily being recognized such as“Hi TV,” “TV,” etc. As described above, the user may input a voicerecognition start command through an input button included in the remotecontroller 300 or the image display apparatus main body 100.

As described above, the user-side audio signal may include a user voicesignal and an audio signal output through the audio output unit 122. Ifthe user-side audio signal includes such background sound, the voicerecognition rate of the first voice recognizer 210 may be deteriorated.If the first controller 220 decreases the volume of the audio signaloutput through the audio output signal 122 to a predetermined levelwhile voice recognition is performed, only the user voice signal isextracted even when the user-side audio signal includes backgroundsound, thereby easily recognizing the control command.

The predetermined volume level may indicate a volume level capable ofensuring a predetermined voice recognition rate or more even whenbackground sound is included. For example, if a volume capable ofensuring a voice recognition rate of 80% or more is 5, the volume of theaudio signal output through the audio output unit 122 may be set to bedecreased to 5 when the voice recognition start command is received. Thepredetermined volume may be previously set in a manufacturing processthrough experimentation or statistical analysis or may be previously setby a user.

The predetermined volume level may not be 0. For example, a user mayinput a control command to select content through voice recognition inorder to view an album stored in the image display apparatus 1 whilelistening to music through the image display apparatus 1. At this time,if the volume of the audio signal output from the audio output unit 122is set to 0 to perform a mute function, operation continuity is notachieved and user intention to simultaneously perform several operationsis not achieved. Accordingly, the predetermined volume may beappropriately selected in consideration of operation continuity andvoice recognition rate.

In addition, the first controller 220 may maintain the current volumelevel if the current volume level is determined to be equal to or lessthan the predetermined volume level.

If voice recognition ends, the first controller 220 returns the volumelevel of the audio signal output from the audio output unit 122 to theoriginal level. If a voice recognition end command is received throughthe first voice input unit 112, if a control command to be subjected tovoice recognition is not received for a predetermined reference time, orif a voice recognition end command is received through an input buttonincluded in the remote controller 300 or the image display apparatusmain body 100, it may be determined that voice recognition ends.

FIG. 3 is a block diagram showing a control flow of an image displayapparatus 1 according to an exemplary embodiment, which further includesa background sound canceller 270.

In the exemplary embodiment of FIG. 3, descriptions of the same portionsas FIG. 2 will be omitted and the background sound canceller 270 will befocused upon for convenience of description.

As described above, if the user-side audio signal includes backgroundsound, the voice recognition rate of the first voice recognizer 210 isdeteriorated and a voice signal having good quality may not betransmitted to the other party if video communication is performed.Accordingly, the image display apparatus 1 according to the presentexemplary embodiment may further include the background sound canceller270 to cancel or reduce background sound from the user-side audiosignal.

The background sound canceller 270 may be implemented by an acousticecho canceller. The acoustic echo canceller receives a reference signaland a user-side audio signal including a user voice signal andbackground sound and cancels the background sound from the receiveduser-side audio signal based on the reference signal. In the imagedisplay apparatus 1 according to the present exemplary embodiment, theaudio signal output through the audio output unit 122 is set to thereference signal and the audio signal output through the audio outputunit 122 is cancelled from the user-side audio signal input to thebackground sound canceller 270. In addition, if the user views abroadcast program, the audio signal received by the broadcast signalreceiver 230 may be set as a reference signal and, if content isexecuted, the audio signal generated by the content execution unit 240may be set as a reference signal.

The user-side audio signal, from which background sound is cancelled bythe background sound canceller 270, is transmitted to the first audiorecognizer 210. If the user inputs a voice recognition start command asa voice signal, the user-side audio signal is transmitted to the firstaudio recognizer 210 in a state in which the volume level of the audiooutput unit 122 is not decreased. Accordingly, if the background soundcanceller cancels background sound, the voice recognizer may easilyrecognize the voice recognition start command.

However, even when the background sound canceller 270 cancels backgroundsound, if the volume of the audio signal output through the audio outputunit 122 is equal to or greater than a predetermined level, it isdifficult to divide the user voice signal and the background soundsignal and cancel only the background sound signal. Even when thebackground sound canceller 270 cancels the background sound signal tosome extent, residual sound of background sound may be present and thusthe voice recognition rate of the first voice recognizer 210 may bedecreased.

In addition, voice recognition errors may be reduced using only thebackground sound canceller 270 by setting the voice recognition startcommand word to a simple word capable of being easily subjected to voicerecognition. However, since other control command words are longer andmore complicated than the voice recognition start command word, it maybe difficult to obtain a desired voice recognition rate only bycancelling background sound. Accordingly, in an exemplary embodiment,after it is determined that the voice recognition start command isreceived in the first voice recognizer 210, the first controller 220 maydecrease the volume of the audio output unit 122 to a predeterminedlevel, thereby further improving voice recognition performance.

FIG. 4 is a block diagram showing a control flow of an image displayapparatus 1 according to an exemplary embodiment, which further includesa command word generator 280.

As shown in FIG. 4, the image display apparatus 1 may further includethe command word generator 280 to allow a user to generate a commandword.

The command word generator 280 includes a command word receiver 281 toreceive a candidate command word from a user, a test unit 282 (e.g.,tester) to test whether the received candidate command word is suitableas a control command word and a setting unit 283 (e.g., setter) todetermine whether the candidate command word is registered according tothe test result of the test unit 282.

The command word generator 280 may generate all command words to berecognized by the image display apparatus 1 and is particularly used togenerate a voice recognition start command word.

As described above, if a user-side audio signal includes backgroundsound, voice recognition performance is deteriorated. In particular, ifthe volume level of background sound is significantly high, even whenthe background sound canceller 270 cancels the background sound, voicerecognition errors may occur. If it is determined that the voicerecognition start command is received in the first voice recognizer 210,the volume of the audio output unit 122 is decreased to a predeterminedlevel. However, since the voice recognition start command is received ina state in which the volume of the audio output unit 122 is notcontrolled, the voice recognition start command word may be set to aword capable of being easily recognized by the voice recognizer evenwhen the volume of background sound is high.

More specifically, the user may register and use a new command word inaddition to a command word which is previously set in the image displayapparatus. If the user inputs a new command word through the first voiceinput unit 112 as a candidate command word, the command word receiver281 receives a voice signal related to the candidate command word.

The test unit 282 tests whether the candidate command word received bythe command word receiver 281 is suitably used as the voice recognitionstart command. In other words, the test unit 282 determines whether thecandidate command word may be easily recognized by the voice recognizeror whether a predetermined voice recognition rate is maintained evenwhen the candidate command word and background sound are simultaneouslyreceived.

The setting unit 283 determines whether the candidate command word isregistered according to the test result of the test unit 282. Forexample, if the voice recognition rate of the candidate command word is80% or more as the test result of the test unit 282, the candidatecommand word is registered as the voice recognition start command wordand is transmitted to the first voice recognizer 210. Thereafter, if theregistered command word is received through the first voice input unit112, the first voice recognizer 210 recognizes the received command wordas the voice recognition start command word and sends a signal to thefirst controller 220.

If the user inputs and registers a plurality of candidate command words,a command related to command word selection may be received from theuser and the command word according to the selection command of the usermay be set as the voice recognition start command word. If the pluralityof command words is registered as the voice recognition start commandword, the first voice recognizer 210 determines that the voicerecognition start command is received if any one of the plurality ofcommand words is received through the first voice input unit 112.

FIG. 5 is a diagram showing the appearance of a remote controller 300included in an image display apparatus 1 according to an exemplaryembodiment.

Referring to FIG. 5, the remote controller 300 includes input buttons320 to receive a control command of a user through touch or buttonmanipulation, and a second voice input unit 312 (e.g., second voiceinputter) (see FIG. 6) to receive a control command of a user throughvoice.

The input button 320 includes a power button 321 to power the imagedisplay apparatus 1 on or off, a volume control button 323 to controlthe volume of the audio signal output from the image display apparatus1, a channel change button 325 to change a channel of a broadcastdisplayed through the image display apparatus 1, and a voice recognitionbutton 327 to receive a voice recognition start command.

The input button 320 may include a switch such as a button-type switchor a membrane switch or a touch pad to sense touch of a part of a user'sbody. The switch and the touch pad may be used interchangeably. Forexample, the power button 321, the volume control button 323, and thechannel change button 325 which are frequently used by the user mayemploy a touch pad and the voice recognition button 327 may employ amembrane switch.

The second voice input unit 312 receives a voice signal related to acontrol command from the user. The second voice input unit 312 mayinclude a microphone to convert a sound wave into an electrical signaland may further include an amplifier to amplify the received voicesignal and an analog/digital (A/D) converter to convert the voice signalinto a digital signal.

FIG. 6 is a block diagram showing the control flow of the remotecontroller 300 included in the image display apparatus 1 according to anexemplary embodiment.

Referring to FIG. 6, the remote controller 300 includes an input button320 to receive a control command from the user through touch or buttonmanipulation, a second voice input unit 312 to receive a control commandfrom the user through voice, a second voice recognizer 410 to identify acontrol command from the voice signal received through the second voiceinput unit 312, a second communication unit 460 (e.g., secondcommunicator) to transmit a control signal to the image displayapparatus main body 110, and a second controller 420 to control anoverall operation of the remote controller 300.

The input button 320 and the second voice input unit 312 have beendescribed with reference to FIG. 5 and thus a description thereof willbe omitted herein.

The second communication unit 460 transmits a control signal to theimage display apparatus main body 100. The second communication unit 460may employ a wireless communication scheme such as a Wi-Fi communicationscheme, a Bluetooth communication scheme, a ZigBee communication scheme,etc., or may employ a relatively simple infrared communication scheme.

The second controller 420 controls the second communication unit 460according to the control command received through the input button 320or the second voice recognizer 410 and transmits a control signal to theimage display apparatus main body 100. More specifically, if an audioincrease/decrease command or a channel change command is receivedthrough the input button 320, the audio increase/decrease command or thechannel change command is transmitted to the image display apparatusmain body 100 through the second communication unit 460.

If the voice recognition start command is received through the voicerecognition button 327 provided in the input button 320, the voicerecognition start command is transmitted to the image display apparatusmain body 100 and a control command identified by the second voicerecognizer 410 is transmitted to the image display apparatus main body100 through the second communication unit 460. The voice recognitionbutton 327 to receive the voice recognition start command from the usermay be provided in the image display apparatus main body 100. Inaddition, the voice recognition start command may be received through amenu provided by the image display apparatus main body 100.

The first controller 220 provided in the image display apparatus mainbody 100 may decrease the volume of the audio signal output through theaudio output unit 122 to a predetermined level if the voice recognitionstart command is received from the remote controller 300 or may decreasethe volume of the audio signal output through the audio output unit 122to a predetermined level if the control command is received from theremote controller 300 through voice.

In addition, if voice recognition ends, the second controller 420transmits a voice recognition end command to the image display apparatusmain body 100 through the second communication unit 460 and the imagedisplay apparatus main body 100 returns the volume of the audio signaloutput through the audio output unit to the original level. Voicerecognition ends when the user inputs the voice recognition end commandthrough the voice recognition button 327 or when a control command to besubjected to voice recognition is not received for a predeterminedreference time.

As compared to the image display apparatus main body 100, since theremote controller 300 receives a voice command of the user at arelatively short distance, the remote controller 300 may not include abackground sound canceller to cancel background sound. However, it isunderstood that one or more other exemplary embodiments are not limitedthereto and the remote controller 300 may include a background soundcanceller.

Hereinafter, a method of controlling an image display apparatus 1according to an exemplary embodiment will be described.

FIG. 7 is a flowchart illustrating a control method of an image displayapparatus 1 according to an exemplary embodiment.

Referring to FIG. 7, first, a user-side audio signal is received from auser through the first voice input unit 112 (operation 511). Theuser-side audio signal may include a user voice signal and an audiosignal output through the audio output unit 122 of the image displayapparatus 1.

A determination as to whether the received user-side audio signalrepresents a voice recognition start command is made (operation 513).That is, a determination as to whether the voice recognition startcommand has been received is made. More specifically, the voicerecognizer 210 determines whether the received user-side audio signalmatches a previously stored voice recognition start command word todetermine whether the voice recognition start command has been received.

If it is determined that the received user-side audio signal representsthe voice recognition start command (Yes of operation 513), then thevolume of the audio output unit 122 is decreased to a predeterminedlevel (operation 515). The predetermined volume level may beexperimentally or statistically set in consideration of a voicerecognition rate or may be set or changed by a user.

A determination as to whether voice recognition has ended is made(operation 517) and, if it is determined that the voice recognition hasended (Yes of operation 517), the volume of the audio output unit 122 isreturned to the original level (operation 519).

FIG. 8 is a flowchart illustrating the exemplary embodiment of FIG. 7 ingreater detail.

Referring to FIG. 8, first, a user-side audio signal is received from auser through the first voice input unit 112 (operation 521) and abackground sound signal is cancelled from the received user-side audiosignal (operation 523). The background sound signal may be an audiosignal output through the audio output unit. An acoustic echo canceller(ACE) may be used to cancel background sound, receives a user-side audiosignal as an input signal, and receives an audio signal output throughthe audio output unit 122 as a reference signal.

A determination 525 as to whether the voice recognition start commandhas been received is equal to that of FIG. 7.

If it is determined that the voice recognition start command has beenreceived (Yes of operation 525), that is, if it is determined that thereceived user-side audio signal represents the voice recognition startcommand, a determination as to whether the current volume level of theaudio output unit 122 exceeds a predetermined level is made (operation527).

If it is determined that the current volume level of the audio outputunit 122 exceeds the predetermined level (Yes of operation 527), thevolume of the audio output unit 122 is decreased to the predeterminedlevel (operation 529) and, if not, the current volume of the audiooutput unit 122 is maintained.

A determination as to whether voice recognition has ended is made(operation 531). The determination as to whether voice recognition hasended is made by determining whether the user inputs a voice recognitionend command or whether a control command of a user is not received for apredetermined time. The voice recognition end command may be receivedthrough voice, manipulation of the input button included in the remotecontroller 300 or the image display apparatus main body 100, or motionrecognition.

If it is determined that voice recognition has ended (Yes of operation531), the volume of the audio output unit 122 is returned to theoriginal level (operation 533). If the volume level of the audio outputunit 122 is equal to or less than the predetermined level and thus ismaintained when starting voice recognition, the volume level of theaudio output unit 122 is maintained even when voice recognition ends.

FIG. 9 is a flowchart illustrating a control method of an image displayapparatus 1 according to another exemplary embodiment.

Referring to FIG. 9, the image display apparatus 1 determines whether avoice recognition start command has been received (operation 611). Morespecifically, if a predefined voice recognition start command word(e.g., “Hi TV,” “TV,” etc.) is received through the first voice inputunit 112 provided in the image display apparatus main body 100 or if thevoice recognition start command is received through the voicerecognition button 327 provided in the remote controller 300 or thevoice recognition button provided in the image display apparatus mainbody 100, the image display apparatus 1 determines that the voicerecognition start command has been received and enters the voicerecognition mode. In addition, if voice having a predetermined volume ormore is received through the second voice input unit 312 provided in theremote controller 300 or the first voice input unit 112 provided in theimage display apparatus main body 100, the image display apparatus 1determines that that the voice recognition start command has beenreceived and enters the voice recognition mode.

If the voice recognition start command word is received through thevoice input unit 112 provided in the image display apparatus main body100, the image display apparatus 1 cancels a background sound signalother than the voice recognition start command word through thebackground sound canceller 270, thereby more accurately recognizing thevoice recognition start command word received through the voice inputunit 112.

If the voice recognition start command is received, the image displayapparatus 1 decreases the volume of the audio output unit 122 to apredetermined volume level (operation 613). At this time, if the volumelevel of the audio output unit 122 is equal to or less than thepredetermined volume level, an operation to decrease the volume of theaudio output unit 122 of the image display apparatus 1 may not beperformed.

Next, the image display apparatus 1 controls the broadcast signalreceiver 230, the content execution unit 240, and the audio output unit122 according to the voice control command of the user received throughthe voice input unit 121 (operation 615). Control of the image displayapparatus according to the voice control command of the user will bedescribed in detail with reference to FIG. 12.

Next, the image display apparatus 1 determines whether voice recognitionends (operation 617). For example, if the predefined voice recognitionstart command word (e.g., “Hi TV,” “TV,” etc.) is received again or apredefined voice recognition end command word is received through thefirst voice input unit 112 provided in the image display apparatus mainbody 100 or if the voice recognition button 327 provided in the remotecontroller 300 or the voice recognition button provided in the imagedisplay apparatus main body 100 is selected in the voice recognitionmode, the image display apparatus 1 determines that the voicerecognition end command has been received. In addition, if a controlcommand is not received from the user through voice for a predeterminedtime, voice recognition ends. Ending of voice recognition because thecontrol command is not received from the user through voice for thepredetermined time will be described in detail with reference to FIG.10.

If it is determined that voice recognition ends, the voice recognitionmode of the image display apparatus 1 is released and the volume of theaudio output unit 122 is returned to the original level (operation 619).

FIG. 10 is a flowchart illustrating a control method of an image displayapparatus 1 according to another exemplary embodiment.

Referring to FIG. 10, the image display apparatus 1 determines whether avoice recognition start command word has been received (operation 711).More specifically, if the predefined voice recognition start commandword (e.g., “Hi TV,” “TV,” etc.) is received through the first voiceinput unit 112 provided in the image display apparatus main body 100, ifthe voice recognition start command is received through the voicerecognition button 327 provided in the remote controller 300 or thevoice recognition button provided in the image display apparatus mainbody 100, or if voice having a predetermined volume or more is receivedthrough the second voice input unit 312 provided in the remotecontroller 300 or the first voice input unit 112 provided in the imagedisplay apparatus main body 100, the image display apparatus 1determines that the voice recognition start command has been received.

If the voice recognition start command has been received, the imagedisplay apparatus 1 determines whether voice having a predeterminedvolume or more has been received through the first voice input unit 112or the second voice input unit 312 (operation 713).

If voice having a predetermined volume or more has been received, theimage display apparatus 1 decreases the volume of the audio output unit122 to a predetermined volume level (operation 715). That is, while thevolume of the audio output unit 122 is immediately decreased when voicerecognition begins in the control method of the exemplary embodimentillustrated in FIG. 9, the volume of the audio output unit 122 isdecreased when a user inputs a control command through voice after voicerecognition begins in the control method according to the presentexemplary embodiment. Through such control, it is possible to ensurecontinuity of operation which is being performed by the user.

Next, the image display apparatus 1 controls the components included inthe image display apparatus 1 according to the control command of theuser through voice (operation 717).

Next, the image display apparatus 1 determines whether voice having apredetermined volume or more has been received again through the firstvoice input unit 112 or the second voice input unit 312 (operation 719).

If voice having a predetermined volume or more has been received, theimage display apparatus 1 controls the components included in the imagedisplay apparatus 1 according to the control command of the user throughvoice (operation 717). However, if voice having a predetermined volumeor more has not been received for a predetermined reference volumedecrease time or more (operation 721), the image display apparatus 1returns the volume of the audio output unit 122 to the original level.

That is, the image display apparatus 1 decreases the volume of the audiooutput unit 122 if voice having a predetermined volume or more isreceived after entering the voice recognition mode and returns thevolume of the audio output unit 122 to the original level if a controlcommand is not received through voice for a predetermined referencevolume decrease time.

Next, the image display apparatus 1 determines whether voice recognitionends (operation 725).

FIG. 11 is a flowchart illustrating a method of finishing voicerecognition if a control command is not received from a user throughvoice for a predetermined time, according to an exemplary embodiment.

As shown in FIG. 11, when the image display apparatus 1 enters a voicerecognition mode, a standby time is initialized (operation 621) and avoice recognition end time is set to a first reference time (operation623). The standby time refers to a time for which the image displayapparatus 1 waits until a user inputs a control command through voice ina voice recognition mode. In addition, the first reference time refersto a time for which the image display apparatus 1 waits when a user doesnot input a control command after entering the voice recognition mode.

Thereafter, the image display apparatus 1 determines whether the controlcommand of the user has been received through voice (operation 625).

If the control command of the user has been received through voice, theimage display apparatus 1 controls the broadcast signal receiver 230,the content execution unit 240, and the audio output unit 122 accordingto the control command of the user (operation 627).

Thereafter, the image display apparatus 1 initializes a standby time(operation 631) and sets a voice recognition end time to a secondreference time (operation 633). The second reference time refers to atime for which the image display apparatus 1 waits until a next controlcommand of the user is received through voice after the image displayapparatus 1 enters the voice recognition mode and the user inputs thecontrol command through voice. Since time is consumed when the userinputs the control command and checks an operation of the image displayapparatus 1, the second reference time may be greater than the firstreference time. For example, if the first reference time is set to 30seconds, the second reference time may be set to 60 seconds inconsideration of the time for the user to check operation of the imagedisplay apparatus 1 according to the control command.

Thereafter, the image display apparatus 1 determines whether the controlcommand of the user has been received again through voice (operation625).

If the control command of the user has not been received through voice,the image display apparatus 1 determines whether the standby timeexceeds a command request time (operation 635). The command request timerefers to a predetermined time interval to request a control commandfrom the user if the user does not input the control command throughvoice. The command request time may be shorter than the voicerecognition end time, in order to request the control command from theuser at least one time before voice recognition ends.

If the user does not input the control command through voice during thecommand request time, the image display apparatus 1 may output amessage, e.g., “Please say a function,” “Would you like to changechannel?” or “Would you like to control volume?” through at least one ofthe video output unit 121 and the audio output unit 122, and requeststhe user to input the control command (operation 637).

Thereafter, the image display apparatus 1 determines whether the standbytime exceeds the voice recognition end time (operation 639).

If the standby time of the image display apparatus 1, that is, the timefor which the user does not input the control command through voice, isequal to or greater than the voice recognition end time, the imagedisplay apparatus 1 finishes voice recognition (operation 641).

FIGS. 12A-12C are diagrams showing a screen displayed on a video outputunit 121 if an image display apparatus 1 according to an exemplaryembodiment is in a voice recognition mode.

Referring to FIG. 12A, control related icons are displayed at the lowerside of the video output unit 121 and a main screen is displayed in theremaining region. Among the icons displayed at the lower side of thevideo output unit, a “power on/off” icon 121 a corresponds to controlcommands “power on” and “power off,” a “volume up/down” icon 121 bcorresponds to control commands “volume up” and “volume down,” and a“channel up/down” icon 121 c corresponds to control commands “channelup” and “channel down.”

Although six icons corresponding to these control commands may bedisplayed in a related art display apparatus, the image displayapparatus 1 according to the present exemplary embodiment may displayonly three icons to execute the six control commands.

If the user inputs a control command corresponding to power on or poweroff, a cursor displayed on the video output unit 121 is moved to the“power on/off” icon 121 a and power is turned on or off according to thecontrol command. The remaining icons 121 b and 121 c may be manipulatedusing a similar method.

Although all contents of one icon are displayed in FIGS. 12A-12C, only“volume” may be displayed with respect to a volume control icon, only“channel” may be displayed with respect to a channel control icon, andonly “power” may be displayed with respect to a power control icon. Thecontents of the icon are not limited so long as the user can recognizewhich control is performed using the icon.

Power on and power off, volume up and volume down, and channel up andchannel down may be executed in a toggle form. For example, if the userinputs a control command word corresponding to “channel up” through thefirst voice input unit 112, as shown in FIG. 12B, a cursor 121 d ismoved to the “channel up/down” icon 121 c and the color of the “channelup/down” icon 121 c may be changed to red in order to distinguishbetween a channel up command and a channel down command. If the userinputs a control command word corresponding to “channel down,” as shownin FIG. 12C, a cursor 121 d is moved to the “channel up/down” icon 121 cand the color of the “channel up/down” icon 121 c may be changed toblue.

As another example, if a control command word is received, an iconcorresponding to the control command word may be flickered or, if acontrol command word corresponding to “channel up/down” or a controlcommand word corresponding to “volume up/down” is received, a verticalbar may be generated in the icon to display a channel control amount ora volume control amount.

Although the cursor 121 d is displayed on the video output unit 121 inFIGS. 12A-12C, it is understood that one or more other exemplaryembodiments are not limited thereto and only the icon may be changedwithout displaying a cursor.

The image display apparatus 1 according to the present exemplaryembodiment may change the icon using various methods in order torepresent that the control command word corresponding to the icon isreceived. Icon change includes displaying a cursor in an icon. Theembodiments of the present invention are not limited to theabove-described examples.

Although only the icons related to power, channel, and volume controlare shown in FIGS. 12A-12C, icons corresponding to various controlcommands such as web browser on/off, mute on/off, etc., may bedisplayed.

FIG. 13 is a flowchart illustrating a method of generating a commandword by a user in an image display apparatus 1 according to an exemplaryembodiment, and FIGS. 14A-14D are diagrams showing a screen displayed ona video output unit 121 if an image display apparatus 1 according to anexemplary embodiment generates a command word by a user. In the presentexemplary embodiment, a voice recognition start command word isgenerated.

Referring to FIG. 13, first, a command word generation request isreceived from a user (operation 811). The command word generationrequest may be received through voice recognition or throughmanipulation of an input button included in the remote controller 300 orthe image display apparatus main body 100 or through motion recognition.The method of inputting the command word generation request is notlimited.

More specifically, as shown in FIG. 14A, first, the user selects a“command word generation” item among menu items related to environmentsettings. The “command word generation” item may also be selectedthrough voice recognition or through manipulation of an input buttonincluded in the remote controller 300 or the image display apparatusmain body 100 or through motion recognition.

Then, a candidate command word is received from the user (operation813). The candidate command word may be received through the first voiceinput unit 112 as a voice signal.

More specifically, as shown in FIG. 14B, if a message, “Enter candidatecommand word,” is displayed on the video output unit 121 of the imagedisplay apparatus 1, the user enters a candidate command word to beregistered as a command word through the first voice input unit 112. Forexample, the user may enter a short word “mic” as the candidate commandword.

If the candidate command word is received, it is tested whether thereceived candidate command word is suitable as the voice recognitionstart command word (operation 815). A short word capable of being easilyvoice-recognized is suitable as the voice recognition start commandword. Therefore, it may be tested whether the candidate command word issuitable using various criteria and a voice recognition rate of thecandidate command word may be measured.

More specifically, as shown in FIG. 14C, a message, “Test is beingperformed,” is displayed on the video output unit 121.

If the candidate command word is suitable as the voice recognition startcommand word according to the test result (Yes of operation 817), thecandidate command word is registered as the voice recognition startcommand word (operation 819) and is transmitted to the voice recognizer.In an exemplary embodiment, if the voice recognition rate of thecandidate command word is equal to or greater than a predeterminedreference value (e.g., 80%), it may be determined that the candidatecommand word is suitable as the voice recognition start command word.

If the candidate command word is not suitable as the voice recognitionstart command word as the test result (No of operation 817), as shown inFIG. 9, another candidate command word may be received from the user orcommand word generation may end according to user selection.

More specifically, if the test ends, as shown in FIG. 14D, the testresult is displayed. For example, if the candidate command word issuitable for registration as the voice recognition start command, amessage, “Registration Possible,” is displayed on the video output unit121. If the candidate command word is not suitable as the voicerecognition start command word and thus a message, “Registration NotPossible,” is displayed on the video output unit 121, the user may entera new candidate command word again.

Although generation of the voice recognition start command word isdescribed with reference to FIGS. 13 and 14A-14C, it is understood thatone or more other exemplary embodiments are not limited thereto and areapplicable to generation of other control commands. The video outputunit 121 of the image display apparatus 1 may display various messagesrelated to command word generation.

In exemplary embodiments, if the control command of the user is receivedthrough voice recognition, the user says a control command withouttaking an action such as pressing an input button, thereby convenientlyexecuting a desired operation.

In addition, the icon corresponding to the control command is displayedon the video output unit 121. For example, a “channel up” icon, a“channel down” icon, a “volume up” icon, and a “volume down” icon may bedisplayed. In particular, since the icons are for operation of the imagedisplay apparatus 1, the icons are displayed in a part of the videooutput unit 121 when a main screen is displayed on the video output unit121.

Since the size of the video output unit 121 is restricted, the number ofdisplayable icons is restricted. The image display apparatus 1 accordingto another exemplary embodiment may display one icon corresponding to aplurality of control command words in order to efficiently manage thearea occupied by the icons.

While the above-described exemplary embodiments are with reference to adisplay apparatus 1, it is understood that one or more other exemplaryembodiments are not limited thereto. For example, other exemplaryembodiments may be applicable to an audio/video receiver, a set-top box,a standalone device, etc., which is capable of performing, implementing,enabling, or controlling voice recognition and/or audio output.

While not restricted thereto, an exemplary embodiment can be embodied ascomputer-readable code on a computer-readable recording medium. Thecomputer-readable recording medium is any data storage device that canstore data that can be thereafter read by a computer system. Examples ofthe computer-readable recording medium include read-only memory (ROM),random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, andoptical data storage devices. The computer-readable recording medium canalso be distributed over network-coupled computer systems so that thecomputer-readable code is stored and executed in a distributed fashion.Also, an exemplary embodiment may be written as a computer programtransmitted over a computer-readable transmission medium, such as acarrier wave, and received and implemented in general-use orspecial-purpose digital computers that execute the programs. Moreover,it is understood that in exemplary embodiments, one or more units of theabove-described apparatuses can include circuitry, a processor, amicroprocessor, etc., and may execute a computer program stored in acomputer-readable medium.

Although a few exemplary embodiments have been shown and described, itwould be appreciated by those skilled in the art that changes may bemade in these exemplary embodiments without departing from theprinciples and spirit of the inventive concept, the scope of which isdefined in the claims and their equivalents.

What is claimed is:
 1. A display apparatus comprising: a display; acommunication unit to communicate with an external device; an audiooutput unit to output an audio signal; and a controller, in response toreceiving a control signal from the external device while displaying animage corresponding to a content on the display and outputting an audiocorresponding to the content through the audio output unit, to activatea speech recognition and control an output volume of the audio outputunit, and in response to deactivating the speech recognition, to restorethe output volume of the audio output unit to a volume level set beforethe speech recognition started, wherein the external device includes aremote controller, the remote controller comprising: a user interfacefor generating the control signal for the display apparatus to activatethe speech recognition; an audio receiver to receive an audio input; anda communicator to communicate with the display apparatus, thecommunicator transmitting signals corresponding to the audio inputreceived via the audio receiver to the display apparatus of which thespeech recognition is activated, and wherein the speech recognition iscapable of being activated while the content is being viewed.
 2. Thedisplay apparatus according to claim 1, wherein the controller controlsthe output volume by decreasing the output volume to a predeterminedlevel while continuing to display the content being viewed.
 3. Thedisplay apparatus according to claim 1, wherein the controller controlsthe audio output unit to decrease the output volume to a predeterminedlevel.
 4. The display apparatus according to claim 3, wherein thecontent being viewed comprises a broadcast program providedindependently from the speech recognition.
 5. The display apparatusaccording to claim 1, wherein the controller deactivates the speechrecognition when an audio input for speech recognition is not receivedduring a predefined time after activating the speech recognition, andrestores an output volume to the volume level set before the speechrecognition started.
 6. The display apparatus according to claim 3,wherein the controller deactivates the speech recognition when an audioinput for speech recognition is not received during a predefined timeafter activating the speech recognition, and restores an output volumeto the volume level set before the speech recognition started.
 7. Thedisplay apparatus according to claim 1, wherein the controllerdeactivates the speech recognition when an audio input for speechrecognition is not received during a predefined time after activatingthe speech recognition from the external device, and restores an outputvolume to the volume level set before the speech recognition started. 8.The display apparatus according to claim 3, wherein the controlleroutputs a message requesting an audio input for speech recognition whenan audio input is not received during a predefined time after activatingthe speech recognition.
 9. The display apparatus according to claim 8,wherein the message output by the controller comprises a message imagedisplayed on the display.
 10. The display apparatus according to claim8, wherein the message output by the controller comprises an audiomessage output by the audio output unit.
 11. The display apparatusaccording to claim 3, further comprising: a broadcast signal receiver toreceive a broadcast signal including a video signal and an audio signal;a signal processor to process the received broadcast signal and displayas the broadcast program.
 12. The display apparatus according to claim1, wherein the remote controller transmits data corresponding to theaudio input received by the audio receiver to the display apparatusthrough the communicator.
 13. The display apparatus according to claim12, further comprising a speech recognition unit to analyze the audioinput received from the remote controller.
 14. The display apparatusaccording to claim 1, wherein the audio output unit comprises a speaker.15. An image processing system comprising: a remote controller; and a animage processing apparatus, wherein the remote comprises: a firstcommunication unit to communicate with an image processing apparatus; anaudio receiver to receive an audio input; a user interface forgenerating a control signal for the image processing apparatus toactivate a speech recognition; a first controller, in response to a userinput received via the user interface, to control the firstcommunication unit to transmit a control signal for the image processingapparatus to activate the speech recognition and to transmit signalscorresponding to the audio input to the image processing apparatus ofwhich the speech recognition is activated; and the image processingapparatus comprises: a second communication unit to communicate with thefirst communication unit of the remote controller; an image processingunit to process an image signal; an audio output unit to output an audiosignal associated with the image signal; and a second controller, inresponse to receiving the control signal from the remote controller, toactivate the speech recognition and control an output volume of theaudio output unit, and in response to deactivating the speechrecognition, to restore the output volume of the audio output unit to avolume level set before the speech recognition started, wherein thespeech recognition is capable of being activated while the image signalis being processed.
 16. The image processing system according to claim15, wherein the image processing apparatus further comprises a displayto display the image signal.
 17. The image processing system accordingto claim 16, wherein the second controller controls the output volume bydecreasing the output volume to a predetermined level while the displaydisplays the image signal.
 18. The image processing system according toclaim 15, wherein the second controller controls the audio output unitto decrease the output volume to a predetermined level.
 19. The imageprocessing system according to claim 15, wherein image signal comprisesa broadcast video signal provided independently from the speechrecognition.
 20. The image processing system according to claim 15,wherein the second controller deactivates the speech recognition when anaudio input for speech recognition is not received during a predefinedtime after activating the speech recognition, and restores an outputvolume to the volume level set before the speech recognition started.21. The image processing system according to claim 15, wherein thesecond controller deactivates the speech recognition when an audio inputfor speech recognition is not received from the remote controller duringa predefined time after activating the speech recognition, and restoresan output volume to the volume level set before the speech recognitionstarted.
 22. The image processing system according to claim 15, whereinthe second controller outputs a message requesting an audio input forspeech recognition when an audio input is not received during apredefined time after activating the speech recognition.
 23. The imageprocessing system according to claim 22, wherein the message output bythe controller comprises a message image displayed on a display.
 24. Theimage processing system according to claim 22, wherein the messageoutput by the controller comprises an audio message output by the audiooutput unit.
 25. The image processing system according to claim 15,wherein the image processing apparatus further comprises: a broadcastsignal receiver to receive a broadcast signal including a video signaland an audio signal; and a signal processor to process the receivedbroadcast signal and display as a broadcast program.